Immersion anode



G. c. cox IMMERSION ANODE May 16, 1950 Filed April 22, 1946 2 SheetsSheet l //Vl/E/V 70x? GEO/Q65 C. Cox

G. C. COX

IMMERSION ANODE May 16, 1950 2 Sheets-Sheet 2 Filed April 22, 1945 //v vE/V 7-01? C ox GEORGE C UNITED STATES TENT OFFICE IIVLMERSION ANODE George C. Cox, Charleston, W. Va.

Application April 22, 1946, Serial No. 663,854

Claims.

(Granted under the act of March 3, 1883, as amended April 30, 1928; 370 O. G. 757) The invention described herein may be manufactured and used by or for the Government for governmental purposes, without the payment of any royalty thereon.

conductor as to provide a long life. low cost con nection whose electrical resistance does not substantially increase throughout the life of the apparatus and such that those parts of the lead-in This invention pertains to immersion anodes 5 conductor adjacent to the electrode and which employed, for example, in the decomposition of may be located near or beneath the surface of sea water and similar electrolytes or in dissipatthe electrolyte do not seriously deteriorate even ing an electrical current into a body of substanduring long periods of use. A further object is tially fresh water in situations in which polarizato provide a connection which is very strong ti n p t n ls re mpl y d as an a rr s 1o mechanically and Whose parts do not loosen or aid. The invention is more especially direc ed separate as the result of electrolytic or other to the provision of low resistance contacts and action during use and which affords an electrical long-life connections betweenanommetallicelecpath of ample transverse area to insure low retrode (comprising one or more parts) and its sistance at the junction surfaces even though lead in conductor (cable or bus bar). Practical the apparatus be submerged in saline water for applications of the invention are to be found in long periods. Broadly stated, the invention prothe construction of anodes employed in the DTOC- vides a highly efficient and durable electrical esses described in my United States Patent No. union between a non-metallic anodic-insoluble dated y 1940, related pro s electrode and a metallic conductor by means of In electrolyzing sea water or similar solutions a body of metal having a depressed anodic surcontaining soluble chlorides, as suggested in the face solubility. aforesaid patent, and wherein a non-metallic other and further objects and advantages of electrode is employed, it has been found that the the invention will be pointed out in the followoperative life of the connection between the leading more detailed description and by reference in cable or bus bar and the adjacent surface of to the accompanying drawings wherein the non-metallic electrode is quite short as com- Fig. 1 is a fragmentary more or less diagrampared for example with the life of the electrode matic, diametrical section through an anode as a whole, thus r qu ing a frequent replac united to a lead-in cable by the improved conment of the connections an operation which nections of the present invention; is very expensive and troublesome in installations Fig. 2 is a section on the line 2-2 of Fig. l; of large capacity. This deterioration usually Fig. 3 is a fragmentary side elevation of a manifests itself as a serious increase in the contandard carbon or graphite electrode of cylintact resistance between the terminal block of the drical shape, the end portions of this electrode lead-in conductor (either bus-bar or cable) being shown in diametrical section; and the adjacent non-metallic current carrying Fig. 4 is a diametrical section of a connecting surfaces. Also, the deterioration of such an elecnipple in accordance with one embodiment of trode system has frequently been found to be the present invention; due to the partial or complete anodic solution Fig. 5 is a diametrical section showing the of the lead-in bus bar or cable at or adjacent nipple of Fig. 4 inverted and illustrating one of to its terminal block. Because of the increased the preliminary steps in anchoring the lead-in voltage to force a given current through an cable to the nipple; electrode system having either one or both of Fig. 6 is a diametrical section similar to Fig. these faults, the operating efiiciency becomes 4, but illustrating a modified form of nipple; lowered. Further continued operation with such Fi 7, 3 nd 9 a i n views illustrating faulty parts usually results in an inoperative 4 further modifications; electrode system. Fig. 10 is a similar section illustrating a nipple While various kinds of non-metallic electrodes of tapered form; and have heretofore been proposed and may be used Fig. 11 is a fragmentary, diametrical section effectively in the practice of the present inventhrough a compound anode comprising a plution, the invention is herein specifically described rality of electrodes.

but without intended limitation, in its application to a carbon or graphite electrode.

A principal object of the present invention is to provide a novel method of and means for so uniting a non-metallic electrode to a lead-in Although a non-metallic anode for the electrolysis of saline water may be made as a single piece of material, it is desirable and very economical to form the anode from standard commercial parts. For example, the threaded-nipple type of graphite electrode which is manufactured in an assortment of standard sizes may be easily and cheaply modified for the construction of the anode herein illustrated. Such a standardL electrode is shown in Fig. 3. This electrode is a cylindrical rod i of amorphous carbon or graphite having internally screw-threaded axial bores 2 and 3 at its opposite ends, respectively, for the reception of cylindrical, externally threaded connecting nipples. In constructing an anode in accordance with the present invention, it is convenient, although not necessary, to use such an electrode as that shown in Fig. 3. As a preliminary step this electrode may be and often is divided at a transverse plane such as A-B (Fig. 3) spaced from one end a distance (for instance equaling one-sixth of the length of the electrode) such that it does notintersect the adjacent axial bore. There thus provided a relatively short section 4 (Fig. 3) having the axial,

internally screw-threaded bore 3. This section is designed to form 'a capfor the anode as hereinafter described. Preparatory to such use, the cap section is drilled to provide'an axial passage, of a diameter substantially equal to the diameter of the lead-in cable which is to be employed, this passage extending from the bottom of the bore 3 to the end of the cap.

A standard connecting nipple 6 (Fig. 4) which is externally screw threaded from 'end to end and which is designed to engage the threaded bore of the electrode, is modified in accordance with the present invention by providing it with an axial bore 1 (Fig. 4) extending down from, its upper end B and of'a diameter such as to receive, with a convenient 'sliding.fit,"the insulating sheath 9 of the lead-in cable it. This cable, as illustrated, is of the type having a multiple strand conductor, preferably of tinned copper Wires. Where a maintenance-free, long life deep sea anode is required a good copper multi-strand well insulated welding cable or its equivalent has given excellent maintenance-free service. Also for certain semi-rigid applications of this type anode, a suitably insulated solid bus bar has been found desirable instead of a flexible lead-in cable,

The bore .1 in the nipple is substantially enlarged in diameter at a pointspaced from the end 8 (for example, beginning at a point which is one-third, more or less, of the length of the nipple from the end 3) thus providing a cylindrical packing chamber H. The axial lengthot this chamber may vary, but as here shown it is generally one-third to one-sixth of the length of the nipple. Below the lower end of thechamber H, the bore iscaused to flare downwardly with a conical taper providing'an anchorage chamber i2 which terminates at the lower end is of the nipple. As illustrated in Fig. 4, the peripheral wall of this chamber l2 is provided with a series oraxiallyspaced transverse grooves is, threesuch grooves being illustrated, and which are here shown as substantially semi-circular in crosssection. These grooves are of substantial width, for instance as herein illustrated, of the order "of approximately one-twentieth the axial length of the nipple- These grooves may readily be cut with an internal lathe tool, and although here shown as of semi-circular transversesection, may be-of any other section which, might be preferred.

It is preferred to make the anchorage chamber I2 of tapering form since this admits of. the introduction of a substantial mass or anchoring metal. without unduly weakening the nipple at posed conductor strands.

its mid-portion. However, as hereinafter pointed out, the anchorage chamber may be of other shape without departing from the scope of the invention.

For illustration, in assembling the parts, one procedure is to screw the upper end of the nipple into the axial bore 3 in the cap 4, thus aligning the axial passage in the cap with the bore '3 in the nipple. The insulating sheath 9 of the cable is removed from the end portion of the cable so as to bare the conductor strands H), as shown inFig. 5, and the end of the cable is then drawn in through the axial passage in the cap and the bore 1 in which the insulating sheath 9 should fitwith a minimum of side play. Preferably the sheath 9 extends into the packing chamber H for a distance, for example, of the order of one-half the length of the packing chamber. The cable is so disposed that the ends of the conductor strands it, which usually have been soldertinned, are within the tapering anchorage chamber l2. Packing material 55 of asbestos fiber, wicking, or any of the usual temperature resistant compressible packing materials capable of forming a leak-tight joint,.is now forced into the chamber 1 l around the end of the insulating sheath 9 and around the bare conductor strands where they emerge from the sheath, the packing being driven in very tightly so as to insure a leak-tight joint between the cable and the wall of the chamber H.

The ends of the metallic conductor strands to are now preferably separated and spread apart and the nipple is arranged in the inverted position shown in Fig. 5, and molten metal is poured into the anchorage chamber l2. This metal may, for example, be lead, a lead alloy, preferably capable of forming asolder or alloy union (herein refererd to as a molecular union) with the ex- The molten metal is poured in so as to fill the chamber 22, and care should be taken to prevent the formation of deep pipes in the body of metal when thus introduced.

In solidifying, the body of metal contracts both radially and axially. By reasonof its iaxialcontraction it grips the material of the nipple intervening between adjacent transverse grooves, the internal cooling strains in the metal thus maintaining a substantially perfect electrical contact between the metal and the substance of the nipple. Moreover, the contact surfaces are of substantial extent, thus providing a very gccd path for the electrical current, even though of heavy amperage, and insuring low resistance at the point of union. Likewisean extremely good electrical union is formed between the anchorage metal and the conductor strands, since not only are the latter molecularly united to the metal but they are embedded in the metal and mechanically held by the latter as it contracts.

If the nipple has been made .from a dense nonporous material it may be used Without further treatment. However, if the nipple has been made from the usual porous gra hite material, it should then be impregnated by one of the standard methods with a suitable oil, wax, or resin-impregnatingcompound, thereby waterproofing this assembly.

This nipple assembly is nowscrewed into the bore 2 :in the upper end of electrode l and will give maintenanceree, highly efficient operation over long periods of time.

In Fig. 6 there is illustrated a modified form of nipple, indicatedat l6, which ingeneral is of the same type as the nipple 6 above described, havingthe axial bore l'l leading to the packing chamber 2 l, which in turn opens into the anchoragechamber 22. However, in this instance the anchorage chamber is cylindrical, being of uni form diameter from top to bottom. The pe peripheral wall of this chamber is furnished With a series of transverse grooves or channels M similar to the grooves above described and having the same function. Th operation of assembling the cable with this nipple is substantially identical with that above described.

A further modification is illustrated in Fig. '7, wherein the cylindrical externally threaded nipple 26 is similar to that above described, having the axial bore 27 for the reception of the cable; the packing chamber 3 I; and the anchorage chamber 32. This chamber 32 is cylindrical like that of the nipple of Fig. 6, but instead of a series of independent grooves M, the peripheral wall of the chamber 32 is provided with a helical groove 34, illustrated as a square screw thread. This groove may be continuous, as shown, or interrupted if preferred. It will be seen that by the provision of helical groove 34, whether continuous or interrupted, the nipple is transversely recessed interiorly at intervals along its length. This groove receives the molten metal and functions in the same way as the grooves Is to insure a substantially perfect electrical contact between the body of anchoring metal and the substance of the nipple.

In Fig. 8 a further modification is illustrated wherein the nipple 66, similar to the nipple 6 above described, has the ing chamber H, and the anchorage chamber 12. In this instance the anchorage chamber is provided with the series of spaced transverse recesses 14 in its peripheral wall, said recesses being arranged in any desired manner, but being individually of small circumferential extent. These recesses receive the molten metal and the latter in cooling grips the walls of these recesses very forcibly, thus providing excellent electrical union between the metal and the material of the nipple.

In Fig. 9 a further modification is illustrated. In this instance the nipple 46 may be of the pancake or disk type, being quite short axially as compared with its diameter. This nipple 45 has the axial bore 41 for the reception of the cable; the packing chamber 5|; and the anchorage chamber 52. This anchorage chamber is of large diameter as compared with its axial height, and in practice its axial height need only be sufiicient to insure adequate contact between the metallic anchorage block and the cable conductors. However, its diameter should be suflicient to insure an adequate gripping action between the metal anchoring block and the material of the nipple. To insure this gripping action, the upper part of the chamber 52 is formed with an annular groove 54 which extends transversely of the axis of the chamber and which is undercut so that when the metal is poured into the chamber 52 it will flow into the groove 54 and thus by the radial shrinkage of the metal in cooling will forcibly grip the annulus M between the groove 54 and the chamber 5i so as to insure good electrical contact. If the diameter of the chamber 52 be large enough, as compared with the diameter of the packing chamber 5|, it may be possible, if desired, to provide more than one of the grooves 54 at the upper end of the chamber 52 for the reception of the anchorage metal.

It is thus seen that longitudinal, radial or any axial bore 61, the packother angular shrinkage of a metal terminal block is made to efiect a highly efficient pressure contact between a terminal block and the electrode material which it grips. This same construction effects excellent metal-to-metal contact, usually by a soldering or alloying action of the lead-in connection (either bus bar or cable) to the terminal block.

In Fig. 10 a further modification is illustrated wherein the nipple 86 is of the customary double tapered type designed for use with standard electrodes of the form in which the axial bores, corresponding to the bores 2 and 3 of Fig. 3, are tapered from the outer end of the electrode inwardly. This nipple 86 has the axial bore 81, the packing chamber 9!, and the anchorage chamber 92, here shown as slightly tapered and as provided with grooves similar to the grooves [4 of Fig. 6.

In Fig. 11 there is illustrated a composite anode comprising five electrodes all secured to a current distributing cap 184. Usually this cap Hi4 will be a circular disk, and four of the electrodes will be arranged symmetrically with respect to the center of the disk (only two of these electrodes being shown). These electrodes I may be standard electrodes and are united to the cap I84 by standard electrode nipples I06. The fifth electrode Ill!) is arranged at the center of the distributing cap or disk H14 and is united to the latter by a nipple 5 which may, for example, be like the nipple illustrated in Fig. 4, and above described. Preferably a short length of rubber tubing ii)? is arranged to embrace the sheath 9 of the cable where the latter passes through the disk I M, thus protecting the cable from any possible damage by the sharp upper edge of the hole in the cap which receives the cable.

When a group of electrodes is employed, as suggested, it may be desirable to unite the lower ends of these electrodes by some suitable brace formed of non-conducting material. For instance the lower ends of these electrodes may be secured to a disk similar to the cap IE4, but of non-conducting material. This forms no essential part of the invention and is not here illustrated. The arrangement of Fig. 11 is merely by way of suggestion of possible arrangements of multiple composite electrodes, and it is to be understood that those skilled in the art may assemble a plurality of electrodes in any desired number and in any desired relative arrangement so as to receive current from the distributing cap lil l or its equivalent. Also these electrodes may be attached to the upper side of the cap I04 or to both sides as required.

The metal employed in anchoring the cap to the nipple should be of a type having a depressed or low anodic surface solubility. Lead and some of its alloys are found to develop during use a complex surface film which greatly depresses the anodic solubility of the metal in saline waters or similar electrolytes. Some of the silver alloys have similar characteristics and may be advantageously used. For use with an aluminum bus bar or conductor, the anchorage metal may be aluminum or some of the alloys of aluminum which have the characteristic of forming a simi lar film of low anodic solubility. The ease with which lead or some of the lead alloys may be sweat-soldered or alloyed (molecularly united) to the'end of a copper bus bar or conductor, makes the use of such metals distinctly advantageous in this construction.

When using low anodic solubility anchorage metalinthe nipp1e16,the lower end I 3vmay be exposed directly to the electrolyte. Such a construction, which results bylomitting the fifth center electrode 100 illustrated-sin Figurell is economically important forthe construction of certain lightweightelectrodes.

It will'be obvious that the contact areas-between the conductor or bus bar and the anchorage metal should be designedinaccordance vwith the intended carrying'capacity of the apparatus.

The essential details of the anode construction disclosed herein hasbeen found by many repeated tests to maintain over longlperiods of time an extremely low voltagedrop-between a graphite-electrode andits coacting metallic lead-in conduc- .tor. Such electrodes have operatedin morethan fifty feetlof sea waterathigh efliciency or thousands of hours without any maintenance attention whatever. Based on many tests, there appears to be nollimit-to the-depth in: sea or brackish water at which these electrodes will operate successfully forextended time periods; they are equallyadaptable fordeep water or shallow water use.

While certain desirable embodiments of the inventionhave been illustrated and described by wayof example, :itis to be understood that the inventionis broadly inclusive of any and-allmodificationsialling withinthe scope-ofthe appended claims.

I claim:

1. In combination in a non-metallic electrode comprising two united parts having sci-ewthreaded bores, one of said parts .having lan axial passage eladinglto its bore, an externally screwthreaded graphite nipple whose oppositeends-are received in the bores oic-saidlrespective electrode parts and which firmly unites said parts, said nipple, having an axial bore aligned with the aforesaid passage in the'electrodegpart, saidlbore .in the nipple leading into a packing chamber within the nipple, said chamber merging with an anchorage chamber also in the nipple and'having recesses in its wall, said recesses extending transverse of the .axial bore, an insulated conductor extending throughlth'e axial passage in the.'elec- 'trode and through the axial'bore in'the nipple, and having its cared end'disp'osed in the anchorage chamber, packing within the packing chamber providing a leaktight joint between, the conductor and the wall. of said chamber, and a "body of lead in the anchorage chamber'molecularly-griited to the'bared Lendof the metallic con ductor, said lead adhering to said graphite nip-' ple adiacent the transverse recesses of said an,- -chorage chamber formed therein.

2. An anode comprising a non-metallic *elecrically conducting distributing plate,-a plurality of carbon electrodesan'd means uniting the-eleccommunicating withtheelectrode cavity, a carbonnipple fitting snugly within .both cavities, said-cap member being .formed with-a bore extending therethrough and communicating with its cavity,said nipplelbeing formed with a bore which communicates withand extends away from said cap bore to .form an anchorage chamber communicating with the electrode cavity, an insulated cable conductor extending through said cap boreandsaid nipple bore and having a bared end extending intosaid anchorage chamber, the internal nipple wall which defines said anchorage chamber beingformed with a plurality of longitudinally spaced transverse recesses, and a body of metal of low anodic surface solubility in said anchorage chamber molecularly united to said bared cable and adherent to the internal nipple wall'between adj acent transverse recesses thereof.

a. An anode assembly comprising a carbon electrode formed with, a cavity in its periphery, a cap member formed with a cavity in its, periphery and abutting the electrode with its cavity communicatingwith that of the electrode, a graphite nipple fitting snugly within both cavities, said cap member being formed with a bore extending th'erethrough and communicating with its cavity, said nipple being formed with a bore which communicates with and extendsaway from said cap bore, an anchorage chamber formed within said nipple and communicating at one end with said nipple bore and at its other end with'said electrode cavity, aninsulated cable conductor extending through said cap bore and said-nipple bore, said cable being baredforward of said nipple bore and extending into said anchorage chamber and terminating therein, the internal nipple wall -v'rhich defines'said anchorage 'c'ham'ber being transversely recessed, and an integrally cast body of lead in said anchorage trodes to the plate, themeans for unitingone at least of the electrodes to'the plate comprising-a ;non-metallic electrically conducting nipple having screw tlireaded engagement at its opposite b83618 respectively with "the plate and electrode,

said-nipple and plateshavingaligned'bores, anin- :sulated-conduetor extendingthrough said aligned bores and having a baited Y end disposed within a chamber inthe nipple, and a body of metalembedding the bared end of the conductor and which firmly grips aportion of the "nipple within its substance in response to; internal 'cooling stress.

3. An anode assembly comprising a -.carbon electrode formed with ;a cavity in its periphery, a cap member formed with a cavityrin-itsperiphcry and abutting the electrode with its :cavity chamber united to said bared cable-end and ad- 'herentto the nipple adjacent said transverse recase.

5, An anode assembly comprising a carbon electrode form'ed with a cavity'in its periphery, a cap member "formed with a cavity in its periphlery and abutting the electrode with its cavity communicating with the-electrode cavity, a carbon nipple :iitting snugly within both cavities; .said'capzmemb'er beingv formed witha boreexitending therethrough and communicating with its cavity, said nipplebei'ng formed with a'bore which :c'ommunicates with said cap b'ore and ex- :tends awayfrom said .capbore to'form ananchorage chamber communicating with'the electrode ,.cavity, aninsulatediconductor extending through Said cap bore and said nippleibore and 'havinga bared end extending into said :anchorage chamber, the internal nipple .wall which defines said anchorage chamber bein'g' transversely recessed at intervals longitudinally of the nipple, and 1a body-oi metal voi? low anodic surface solubilityliin isaid anchorage chamber molecularly united .to said bared-conductor and adherent tothe internal nipple wall between longitudinally adjacent :transversely recessed portions.

6. An anode assembly comprising a carbon electrode formed with a cavity %in:its periphery, acarbon nipple :fitting snugly within said cav- "ity, said nipple being formed with a 'bore :for

15 :nipple bore and extending :into said anchorage chamber and terminating therein, the internal nipple Wall which defines said anchorage cham ber being transversely recessed, and an integrally cast body of metal of low anodic surface solubility in said anchorage chamber united to said bared conductor end, and adherent to the nipple adjacent said transverse recess.

7. An anode assembly comprising a carbon electrode formed with a, cavity in its periphery, a carbon nipple fitting snugly within said cavity, said nipple being formed with a bore adapted to receive a conductor, an anchorage chamber formed in said nipple and communicating at one end with said nipple bore and at its other end with said electrode cavity, an insulated eonductor extending through said nipple here, said conductor being bared forward of said nipple bore and extending into said anchorage chamber and terminating therein, the internal nipple wall which defines said anchorage chamber being transversely recessed at intervals longitudinally of the nipple, and an integrally cast body of metal having a coeificient of thermal expansion appreciably greater than that of carbon in said anchorage chamber united to said bared conductor and adherent to the internal nipple wall between longitudinaly adjacent transversely recessed portions.

8. In combination, a carbon externally threaded nipple formed with a longitudinal bore which extends inward from one end, an anchorage chamber formed in said connecting member and communicating with said bore, an insulated conductor extending through said bore, said conductor being bared inward of said bore and extending into said anchorage chamber and terminating therein, the internal wall of said connecting member which defines said anchorage chamber being transversely recessed at intervals longitudinally of the anchorage chamber, and an integrally cast body of metal of low anodic surface solubility in said anchorage chamber molecularly united to said bared conductor, and adherent to the internal wall of said connecting member between longitudinally adjacent transversely recessed portions, said metal having a coefiicient of thermal expansion appreciably greater than that of carbon.

9. In combination, a carbon externally threaded nipple formed with a cavity which defines an anchorage chamber, a conductor extending into said chamber and having a bared portion situated therein, the internal Wall of said connecting member which defines said anchorage chamber being transversely recessed at intervals longitudinally of the anchorage chamber, and a body of lead in said anchorage chamber united to said bared conductor, and adherent to the internal wall of said connecting member between adjacent transverse recesses.

10. In combination, an electrically conductive connecting member formed with a cavity which defines an anchorage chamber, a conductor extending into said chamber and having a bared portion situated therein, a portion of said chamber being defined by an annular groove extending around said conductor transversely thereof, a solid portion of said connecting member adjacent said groove extending around said conductor and extending transversely outward of said conductor to form a shoulder partially interposed between said groove and another portion of said cavity, said shoulder being constructed and arranged such that a restricted passage interconnecting said groove and said other portion of the cavity is formed, and an integrally cast body of metal in said cavity adherent to said bared 7 portion of the conductor and to said shoulder and that portion of the connecting member encompassed by said groove.

GEORGE C. COX.

REFERENCES CITED The following references are of record in the file of this patent:

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